Ventilating fan



Nov. 9, 193?. v M. A. SMITH, JR 2,998,407

VENTILATING FAN Filed June 8, 1936 2 Sheets-Sheet l a2 Q 2 40 1 x I 5351 44' 4 .86 zal a g r i INVENTOR I EL 1 A Newman GJN I v /2 BY MWATTORNEY Nov. 9, 1937. M. A. SMITH. JR 2,098,407

' IVENTILKATING FAN Filed June a, 1936 2 Sheets-Sheet 2 IIIIIIIIIIIIIIL.

. INVENTOR MGRbHGLL Qjmnm, A

ATTORNEY Patented Nov. '9 1937 UNITED STATES PATENT OFFICE 2,098,407 vVENTlL-ATING FAN Marshall A. Smith, Jr., South Bend, 1nd,, as-

signor, by mesne assignments, to Air Devices Corporation, Chicago, 111.,-a corporation of Delaware Application June 8, 1936, Serial No. 84,012

7 Claims.

An object of this invention is therefore to provide a ventilating fanwhereinthe driving motor is resiliently suspended in the supportingcasing, and the driving shaft of the fan is separated from the fanblades by resilient means interposed between the blades and the shaft.

Another object of the invention is to provide a fan driving meanscomprising a spiral gear fixed to the fan shaft adapted to be driven bya worm carried on one end of the motor shaft.

A further object is to provide self -aligning bearings to support themotor shaft which may be readily adjusted to position a worm carried bythe motor shaft in proper operative relation with a spiral gear carriedby the fan shaft.

Another object is to provide anti-friction thrust-absorbing meansadapted to restrain the driving shaft in both directions.

A still further object is to provide a novel thrust bearing forsupporting the weight of the motor rotor and the end thrust of the wormon the motor shaft, comprising a ball interposed between one end of themotor shaft and a hardened disc positioned in a, socket of slightlylarger diameter than the ball whereupon the ball may roll on a smallradius thereby minimizing wear of the parts.

A further object is to provide a novel thrust absorbing support toabsorb thrust developed when the fan is being decelerated, comprising asmall conical point on the upper end of the motor shaft adapted toengage a flat bridge positioned ad jacent the end of the driving shaft.

Yet a further object is to provide a worm driven fan wherein the centerof gravity of the driving motor is suspended directly above the fanshaft.

A further object is to provide novel means for lubricating the worm andpinion driving gear mechanism.

A further object is to provide resilient driving means between the fanshaft and the fan blades.

Yet a further object of the invention is to provide a novel vibrationabsorbing support between the motor housing of the fan and the supportthereof.

Another object of the invention is to provide a ventilating fan ofimproved design which may be manufactured economically. I

A further object is to provide a fan having a rectangular-shapedresilient support which is of the same width as the fan when viewed inside elevation to facilitate packaging the fan.

Other objects and advantages of this invention will appear from thefollowing detailed description considered in connection with theaccompanying drawings submitted for purposes of illustration only, andnot intended to define the scope of the invention, reference being hadfor that purpose to the subjoined claims.

In the drawings, wherein similar reference characters refer to similarparts throughout the several views:

Figure 1 is a side elevation, partly in section of a ventilating fanembodying the present invention;

Figure 2 is a sectional view taken on the line 2-2 of Figure 1; and

Figure 3 is a sectional view taken on the line 3-3 of Figure 1.

Referring more particularly to Figure 1, there is shown for purposes ofillustrating this inven tion a ventilating fan having arectangularshaped base l0 including cushioning member l2.

A resilient strip it of metal or other suitable material is fixed to thebase l0 and supports 'a motor casing Hi. The fan may be clamped at anydesired angle with reference to the base ill by means of a clamping boltl8. A driving motor 20 is resiliently supported within the casing it atone end by means of a metallic strip 22 spot-welded to the casing l6 atone end, and embedded in resili'ent supporting material, 24 secured tothe end of the motor. The other end of the motor is resilientlysupported in the casing l by means of a resilient grommet 26,- whichengages the outer end of a shaft housing 28 having a washer 30 at theouter end thereof in contact with the inner portion of the grommet 28 toprevent the motor from moving forward in the casing It.

The housing 23 receives a shaft 32, to which a fan hub 36 is fixed. Aplurality of fan blades 38 are welded or otherwise secured to the hub38. A

shield 40 engages the forward end of the hub 36, and is spun intocontact with the blades 38 as shown.

A resilient bushing 42 interposed between the fan hub 36 and theshaft 32is longer than the hub 36, and is adopted to be compressed between awasher 44 and a washer 3'! carried by the shaft 32 when a nut 48 isthreaded to the shaft 32.

'Vibration absorbing means are thus interposed ing 58 and a bearingbracket 60 respectively. A- motor rotor 02 is carried by the shaft 52between thebearings 54 and 58. rotor is surrounded -by the motor stator85 interposed between the housing 53 and the bearing bracket .88. Thebearing bracket 88 is bolted to the housing 58 by means of bolts 88projecting through the motor stator 85 and the bearing bracket 88. Theaxis of the motor shaft 52 may be moved slightly to position the worm 58in proper driving relation with the spiral gear 48 by slight movement ofthe bearing bracket 58 with reference to the housing The lower end ofthe shaft 52 rests upon a ball 88 positioned in the socket 18 formed inthe housing 58. The socket III is slightly larger in diameter than theball 68 and is provided with a flat hardened disc 12 upon which the ball68 may roll on a short radius when the shaft 52 revolves. The frictiontorque due to the driving mechanism is reduced to a minimum because theball 88 is permitted to roll around a circle of small radius between theend of the shaft 52 and the hardened disc 12. v

The upper end of the shaft .52 is provided with a small conical point 14adapted to engage a flat metallic bridge 18 carried by the bearingbracket 58 to absorb the thrust transmitted to theshaft 52 when the fanis being decelerated, during which time the blades 38 drive the motor28.

The casing l6 may be formed in two sections as shown, fixed together bymeans of self-tapping The casing I8 is provided with ventilating louvres82 and 84 to permit a free flow of air through the motor assembly toadequately cool it.

The operation of this device is as follows.

When the motor.20 is started the shaft 52 drives the shaft 32,supporting the fan blade 38, through the worm 50 and the spiral gear 48.The downward thrust of the shaft 52 is absorbed by the ball 68interposed between the end of the shaft 52 and the hardened disc 12thereby minimizing the friction in the driving mechanism.

As previously indicated the blades 38 are insulated from the shaft 32 bythe resilient bushing 42, and the motor 28 is insulated from the casingl6 by the resilient grommet 28 and the resilient support 24. Avibrationless, quiet running fan is thus procured. When the fan isdecelerated the shaft 52 is driven by the blade supporting shaft 32,whereupon the shaft 52 moves upwardly in the housing 58, and the conicalpoint I4 engages the bridge 18 to absorb the thrust transmitted,

thereto without excessive friction.

It will be observed that the driving mechanism including the worm andgear, and the thrust resisting mechanism is housed within a singlechamber, which may be packed with lubricant and sealed by a welch plug88. I

The fan may be mounted on the wall by removing the bolt l8 and reversingthe position of the resilient strip i4 with reference to the casingangle in another plane and so constructed and arranged that the centerof gravity of the motor is positioned directly above the supportingshaft, driving means between the driving and supporting shafts, a bladedfan resiliently supported on the supporting shaft, a casing surroundingthe motor, and resilient means supporting the motor in the casing.

2. In a ventilating fan, a casing, a horizontal tubular supportresiliently mounted at each end in said casing, a fan shaft journalledin said support and carrying a bladed fan exteriorly of ,the casing, andmeans for driving said shaft comprising a motor supported solely by saidtubular supportwithin said casing and having a driving shaft connectedwith the fan shaft.

3. In a-ventilating fan, a casing, a horizontal tubular supportresiliently mounted at each end in said casing, a fan shaft journalledin said support and carrying a bladed fan exteriorly of the casing, andmeans for driving said shaft comprising a motor positioned above saidshaft with the center of gravity thereof aligned vertically with the fanshaft, said motor being supported solely by the tubular support withinsaid casing and having a driving shaft connected with thefan shaft. v

4. A fan comprising a supporting member, a substantially horizontal fanshaft rotatably carried by said supporting member, a bladed'fan carriedby said fan shaft, a motor including a driving shaft drivably connectedto said fan shaft, means mounting the motor on said supporting memberand so constructed and arranged that the center of gravity of the motoris directly above the axis of the fan shaft.

5. A fan comprising a supporting member, a substantially horizontal fanshaft rotatably carried by said supporting member, a bladed fan carriedby said fan shaft, a motor including a driving shaft drivably connectedto said fan shaft, means mounting the motor on said supporting memberand so constructed and arranged that the center of gravity of the motoris directly above the axis of the fan shaft a casing surrounding thesupporting member and motor, and resilient means mounting the supportingmember in the casing.

6. A fan comprising a supporting member, a substantially horizontal fanshaft rotatably carried by said supporting member, a bladed fan carriedby said fan shaft, a motor mounted solely on said supporting member anddrivably connected to the fan shaft, a casing surrounding the supportingmember and motor, and resilient means adjacent the ends of said fanshaft for resiliently mounting the supporting member in the casing.

'7. A fan'comprising a supporting member, a fan shaft rotatably carriedby said supporting member, fan blades mounted on said shaft atone end, agear fixed to the shaft adjacent its other end, a motor housing rigidlycarried by said sup porting member, a bearing bracket adjustably securedto said housing, self-aligning bearings carried by said housing andbracket, a motor rotor Journalled in said bearings, a gear membercarried by said rotor for meshing with said first named gear, saidbracket being so constructed and arranged that adjustment thereofrelative to the housing will position said gear member in proper meshingrelation to the gear on the fan shaft. g

. MARSHALL A. SMITH. JR.

